Padlock



Patented. Aug. 8, 1933 PADLooK Elmer B. Stone, New Britain, Oonn., assignor to The American Hardware Corporation, New Britain, Conn., a Corporation of Connecticut Application December 5, 1930. Serial No. 500,222 3 Claims. (CL 70-108) My invention relates to that class of locks embodying a case having a locking shackle projecting from one end thereof, and an object oi my invention, among others, is the construction of a lock of this type with means for preventing its operation without the use of a key.

One form of a lock and in the construction and use of which the objects herein set out, as well as others, may be attained is illustrated in the accompanying drawing, in which- Figure 1 is a side view of a padlock embodying my invention.

- Figure 2 is a View in lengthwise section through the same on a plane passing through the axis of the arms of the shackle.

Figure 3 is a end view of the lock.

Figure 4 is a view in cross section on a plane denoted by the dotted line 1-4 of. Figure 2.

Figure 5 is an isometric view of one end of the key plug.

It has been found possible with different types of padlocks embodying a shackle movably mounted in the lock to engage one arm or said shackle with a locking bolt within the case, to surreptitiously open said look by means of a series of blows delivered in a certain manner, the parts being held in the position caused by said blows by placing a strain upon the shackle or other parts. By skillfully employing this means it has been found possible to unlock the padlocks without the use of a key. My invention illustrated and described herein seeks to avoid such unauthorized opening of a padlock. lvly improved structureembodies a case 5 having a hole 6 to receive the long arm 7 of a shackle mounted upon a spring 8 in the bottom of said hole, the short arm 9 of the shackle engaging within a recess 10 projecting inwardly from the end of the case. A key plug 11 is rotatably mounted-within the case, this plug having the usual key slot, and the case having tumblers 12 of the pin type cooperating with a set of pin tumblers in the key plug to permit rotation of the plug when the tumblers are properly positioned by a keyinserted in the key slot. All of the parts thus far described are of old and Well known construction and will be readily underthe end of a locking bolt 13 slidably mounted in a hole opening into the recess 10, this bolt embodying my invention stood by those skilled in the art, my invention' being seated against a spring 14 in the bottom of said hole which spring forces thebolt normally into the notchin the shackle arm. The bolt is provided onrone side with a notch 15 within which an actuating finger 16 projecting from the end of the key plug 11 extends, the

. notch 15 being enough larger than the finger to permitendwise movement of the bolt 13 sufficiently to disengage its nose 17 from the notch in the short arm of the shackle, this construc- '65 tion also being present in prior devices.

In carrying my invention into effect I provide a stop in the form of a lip 18 extending into the notch, in the'short arm of the shackle from one side of said notch,and I also provide a re- '70 taming lip 19 extending from the nose 17 of the shackle into position to engage the stop lip 18. t will thus be seen that the engagement of the stop and retaining lips18 and 19 will make it practically impossible to effect backward'f movement of the locking bolt 13 by concussion.

It is desirable, for many reasons, that the locking bolt 13 shall be non-rotatable, having a lengthwise movement only. Simplicity of construction may be mentioned as one of these reasons. I have therefore utilized the endwise yielding movement of the shackle to effect my purpose in this respect. In order to enablethe bolt 13 to be readily movedbackward by the operation of the finger 16 in a rotation of the key plug 11 I bevel the engaging edges of the lips 18 and 19 to a slight extent. This will cause an inward movement of the shackle againstthe tension of the spring 8 as the bolt 13 is forced backwardly by the finger 16 in the unlocking op-I 9 eration. To permit such inward movement of the shackle the bottom of the recess 10 is spaced from the end of the short arm'9 of the shackle.

Such parts of the look as have not been here. in specifically set forth 'will be understood to be of old and well known construction and not requiring further explanation.

I claim r 1. A padlock including a case, a shackle, mounted for yielding movement within the case and having a recess with an upturned lip at the mouth of said recess, a locking bolt mounted for sole longitudinal reciprocating movement within the case and having a downturned lip forming a recess between said lip and the body' of the bolt for reception of the lip on the shackle, the end of the bolt being receivable in the recess in the shackle, and means for operating said bolt. 1

2. .A padlock including a case, a shackle mounted for yielding movement within the case and having a recess with an upturned lip at the mouth of said recess, a locking bolt mounted for sole longitudinal reciprocating movement within the case and having a downturned lip forming a recess between said lip and the body of the bolt for the reception of the'lip on the shackle, the end of the bolt being receivable in the recess in the shackle, and a key plug having an actuating finger engaged with said belt for operation thereof.

ELMER B. STONE. 

